The invention relates to a reciprocating-piston machine particularly for an air conditioning system of a motor vehicle.
DE 197 49 727 A1 discloses a reciprocating-piston machine of the type which comprises a machine housing, in which a plurality of pistons are arranged in a circular arrangement around a rotating drive shaft. The drive force is transmitted from the drive shaft, via a driver, to an annular pivoting disc and from the latter, in turn, via a joint arrangement, to the pistons, which are supported so as to be movable parallel to the machine shaft. The pivoting disc is mounted pivotably on a sliding sleeve, which is linearly movably supported on the machine shaft. The pivoting disc slides along on the joint arrangement, which extends around the pivoting disc by means of two sliding blocks in the form of a spherical cap. Provided in the joint arrangement is a center of force transmission which is arranged in the extension of the respectively associated piston axis and which forms the geometrical center of the sliding faces of the spherical sliding blocks. The machine shaft, driver, pivoting disc and joint arrangements are arranged in a so-called drive space in which gaseous working medium of the reciprocating-piston machine is present under a specific pressure. The delivery volume and therefore the stroke of the pistons and the inclination of the pivoting disc relative to the machine shaft are dependent on the pressure ratio between the suction side and pressure side of the pistons or are correspondingly dependent on the pressures in the cylinders, on the one hand, and in the drive space, on the other hand.
Patent specification U.S. Pat. No. 4 762 468 discloses a reciprocating-piston machine in the form of a swashplate compressor with a rotating drive shaft, on which a swashplate is fastened in a fixed position. A plurality of pistons is articulated via the swashplate, so that the piston axes of the pistons are arranged at the same distance from the machine shaft, around the latter on a cylinder envelope. For coupling the swashplate and the pistons, for each piston two sliding elements are provided which are mounted in a receptacle in the form of a spherical segment and located on the associated piston and which slide on the swashplate. The sliding elements are designed cylindrically with a semi-spherical end portion. Because of the constant angle between the swashplate and the drive shaft, the positions of the sliding elements do not change when the compressor is in operation, so that a constant play can be set between the sliding elements and the swashplate.
It is the object of the present invention to provide a reciprocating-piston machine with an improved operating behavior and with improved performance.